Abstract
While the nation state on a policy of a linguistic standardization, multilingual states are now emerging in Europe : Spain, Italy, Switzerland and Belgium have indeed recognized an official status to several regional languages on their national territory. However, the constitutional recognition of the linguistic plurality is not without influence on the identity of the state. On one hand, pluri-officiality establishes a legal link between a language and a territory. In doing so, it has the effect of the emerging of linguistic territories within the state, a factor of decentralization and restructuration : the institutionalized multilinguism reorganizes the state. On the other hand, linguistic plurality pertains to the legal construction of the Nation and thus calls for the determination of new principles and justification of the nation state. On account of the redefinition of the Nation under the effect of the constitutionalization of regional languages, national unity is rephrased in a multilingual Nation that mobilises an ideology of recognition that substitutes to the traditional one of belonging. Multilingual state is a recognition state. The languages adds to the territory, population and Government as constitutive element of the state.